DAC drops out when Furnace starts or stops. HELP


Every time my furnace or water heater (gas, power vented) kicks on or off my DAC drops out momentarily. My audio system, furnace and water heater are all on separate dedicated ac lines. My AC panel was updated to a 200 amp service some years back.
I checked all connections from the panel to each device and internally checked all electrical connections in the furnace and water heater, verifying proper hot, neutral and ground.
I checked and tightened all wires in the service entrance panel.
Has this happened to anyone else? If so what did you do to correct it?
Any help will be appreciated.
jadedavid
Doug, I should clarify my earlier comments about digital cable length by adding that they only pertain to electrical (non-optical) S/PDIF and AES/EBU cables. My comments don't apply to USB cables, in part because the risetimes and falltimes of USB signals are vastly different than those of S/PDIF and AES/EBU signals. As I had mentioned, and as further explained in the paper I linked to, signal risetimes and falltimes are key variables affecting what length will be optimal.

Also, I'll add that if a very short length is practicable, such as perhaps 8 inches or so, that can be expected to often be as good or better a choice for S/PDIF and AES/EBU than 1.5 or 2 meters. It is the intermediate lengths, such as 1 meter, which (depending on a complex and essentially unpredictable set of component-dependent variables), stand a somewhat lesser chance of being optimal than those other choices.

Regards,
-- Al
Amazing I had the same problem with my old dac and cd player I never found out what the problem was My new set up does not do it ??? Good Luck.
Follow up to this thread.

I later contacted the OP, through the Agon message system, with a question about the problem he had with drop outs. I asked him if he was still using the same 1.5M Grover Huffman digital cable. He responded no he had bought a new 1M Grover Huffman digital cable and was not experiencing any drop out problems with the 1M Grover Huffman cable.

Conclusion? Not all S/PDIF 75 ohm digital coaxial cables are created equal.
Was it the RCA connectors used? Do the ends used by Grover Huffman have a closer better 75 ohm characteristic than the ones used by Audio Envy?

Was it how the RCA connectors were connected to the coax cable?

Was it the 75 ohm coax cable Audio Envy used?

Or was it ???





Is it the length of the cable that could be the culprit or is it the design/construction differences?
Or was it ???
-The characteristic impedance of the cable. That is why length is immaterial.

If the characteristic impedance of the cable is incorrect, there will be reflections that cause errors. This can lead to an inability for the DAC to lock onto the signal. The right cable is all that's needed. Not all high end cable manufacturers understand this, so you see a lot of variance. One cable manufacturer that does get this right is Purist Audio.
Hope there are still audiophiles smarter than me still interested in commenting about dropouts because I ran into a similar problem for which I need help with when I introduced the Yggdrasil dac into my system running off a Grover Huffman digital cable (as recommended in this stream) connected to the digital out of my CD player.  I was hearing occasional dropouts which I subsequently was able, thru experimentation, to duplicate/induce by switching on or off a nearby fluorescent fixture or a clothes dryer in an adjacent room. Incandescent switches in the room have no affect. 
Not clear to me yet whether these components share a conmmom AC line.  I have tried several lesser cost different digital cables both coax and xlr with no difference. And, oh yes, the CD player need not be spinning. I can see the sample rate indicators on the Yggdrasil flashing off momentarily when I hit the fluorescent switch